A.周圍有5PPM的硫化氫存在 B.零點(diǎn)漂移,適當(dāng)調(diào)校 C.應(yīng)在檢測時(shí)將檢測數(shù)據(jù)減去5PPM
A.10 B.20 C.100
A.15:2 B.5:1 C.30:2